Integrated circuits are electronic circuits that are typically manufactured from a semiconductor material (e.g. silicon, etc.). Due to the reliability of integrated circuits and developments within the industry that allow integrated circuits to be mass produced, the usage of integrated circuits has become ubiquitous in the manufacture of many commercial electronics equipment produced today and have contributed significantly to the proliferation and development of the electronics industry. Integrated circuits are often combined to form products including various devices or components, which both comprise an underlying computing system, and are integrated as peripheral devices in the computing system, etc.
Integrated circuit developers typically design an integrated circuit with an intended lifetime before failure. During a typical design phase for an integrated circuit, an integrated circuit developer generally specifies the voltages and frequencies at which the integrated circuit or “chip” is going to operate with and/or under. However, these operating conditions (along with temperature) may contribute to aging effects that naturally occur with silicon or like-material based products.
These conditions can change as aging effects and wear are accumulated by an integrated circuit product. For example, a product which requires a certain voltage to operate under a specific frequency at the beginning of the lifetime of the product may require a higher voltage to operate under the same frequency later in the lifetime of the product, due to the aging effect. Moreover, the operating conditions can fluctuate drastically and frequently, depending on usage of the underlying computing system, which, naturally, can vary from user to user. As a result, designing an integrated circuit with sufficient tolerances to last the intended lifespan under such wildly varying conditions can be a complex process.
Further, ever shrinking deep-submicron geometries come with multiple degree of complexity both at design and fabrication. These complexities include thermal management, power distribution, cross-talking, and electromigration. Thus, it is helpful to understand the silicon degradation of an integrated circuit to precisely predict how the system behaves with aging. Silicon degradation refers to deterioration of system performance over time and usage.
One major silicon degradation consequence is change in the threshold voltage of the transistors which significantly determines various factors such as system slack, operating frequency, setup-hold constraints, and on-chip parasitics, among other factors. With continued deep-submicron scaling, reliability issues such as hot carrier injection (HCI), bias temperature instability (BTI), and time-dependent dielectric breakdown (TDDB) have become more prevalent. There is thus a need for addressing these and/or other issues associated with the aging of integrated circuits.